1 files changed, 42 insertions, 21 deletions

diff --git a/generic/tclDictObj.c b/generic/tclDictObj.c
index 61045be..9fad0c8 100644
--- a/generic/tclDictObj.c
+++ b/generic/tclDictObj.c
@@ -70,18 +70,12 @@ static inline void	DeleteChainTable(struct Dict *dict);
 static inline Tcl_HashEntry *CreateChainEntry(struct Dict *dict,
 			    Tcl_Obj *keyPtr, int *newPtr);
 static inline int	DeleteChainEntry(struct Dict *dict, Tcl_Obj *keyPtr);
-static int		FinalizeDictUpdate(ClientData data[],
-			    Tcl_Interp *interp, int result);
-static int		FinalizeDictWith(ClientData data[],
-			    Tcl_Interp *interp, int result);
-static int		DictForNRCmd(ClientData dummy, Tcl_Interp *interp,
-			    int objc, Tcl_Obj *const *objv);
-static int		DictMapNRCmd(ClientData dummy, Tcl_Interp *interp,
-			    int objc, Tcl_Obj *const *objv);
-static int		DictForLoopCallback(ClientData data[],
-			    Tcl_Interp *interp, int result);
-static int		DictMapLoopCallback(ClientData data[],
-			    Tcl_Interp *interp, int result);
+static Tcl_NRPostProc	FinalizeDictUpdate;
+static Tcl_NRPostProc	FinalizeDictWith;
+static Tcl_ObjCmdProc	DictForNRCmd;
+static Tcl_ObjCmdProc	DictMapNRCmd;
+static Tcl_NRPostProc	DictForLoopCallback;
+static Tcl_NRPostProc	DictMapLoopCallback;
 
 /*
  * Table of dict subcommand names and implementations.
@@ -2285,7 +2279,7 @@ DictAppendCmd(
     Tcl_Obj *const *objv)
 {
     Tcl_Obj *dictPtr, *valuePtr, *resultPtr;
-    int i, allocatedDict = 0;
+    int allocatedDict = 0;
 
     if (objc < 3) {
 	Tcl_WrongNumArgs(interp, 1, objv, "dictVarName key ?value ...?");
@@ -2308,17 +2302,44 @@ DictAppendCmd(
 	return TCL_ERROR;
     }
 
-    if (valuePtr == NULL) {
-	TclNewObj(valuePtr);
-    } else if (Tcl_IsShared(valuePtr)) {
-	valuePtr = Tcl_DuplicateObj(valuePtr);
-    }
+    if ((objc > 3) || (valuePtr == NULL)) {
+	/* Only go through append activites when something will change. */
+	Tcl_Obj *appendObjPtr = NULL;
+
+	if (objc > 3) {
+	    /* Something to append */
+
+	    if (objc == 4) {
+		appendObjPtr = objv[3];
+	    } else if (TCL_OK != TclStringCatObjv(interp, /* inPlace */ 1,
+		    objc-3, objv+3, &appendObjPtr)) {
+		return TCL_ERROR;
+	    }
+	}
 
-    for (i=3 ; i<objc ; i++) {
-	Tcl_AppendObjToObj(valuePtr, objv[i]);
+	if (appendObjPtr == NULL) {
+	    /* => (objc == 3) => (valuePtr == NULL) */
+	    TclNewObj(valuePtr);
+	} else if (valuePtr == NULL) {
+	    valuePtr = appendObjPtr;
+	    appendObjPtr = NULL;
+	}
+
+	if (appendObjPtr) {
+	    if (Tcl_IsShared(valuePtr)) {
+		valuePtr = Tcl_DuplicateObj(valuePtr);
+	    }
+
+	    Tcl_AppendObjToObj(valuePtr, appendObjPtr);
+	}
+
+	Tcl_DictObjPut(NULL, dictPtr, objv[2], valuePtr);
     }
 
-    Tcl_DictObjPut(NULL, dictPtr, objv[2], valuePtr);
+    /*
+     * Even if nothing changed, we still overwrite so that variable
+     * trace expectations are met.
+     */
 
     resultPtr = Tcl_ObjSetVar2(interp, objv[1], NULL, dictPtr,
 	    TCL_LEAVE_ERR_MSG);